Method And Device For Operating A Fermentation Plant

Abstract

A fermentation plant with at least one digester ( 1 ) is supplied with a substrate ( 1 a ) that is percolated using a percolate ( 2 a ) from a percolate container ( 2 ) and biogas that is generated via the percolation process in the digester ( 1 ) or/and in the percolate container ( 2 ) is drawn off. The drawn off biogas is treated in a biogas treatment device ( 3 ) and CO 2 -containing exhaust gas that is generated during the treatment is introduced into the substrate ( 1 a ) in the digester ( 1 ) using a purge line ( 4 ), for forcing out the biogas in the substrate ( 1 a ). CO 2 -containing biogas that was generated in an additional digester ( 1 ) in a different fermentation process can be introduced into the substrate ( 1 a ) in the digester ( 1 ) using a purge line ( 4 ). The CO 2 -containing purge gas supplied to the substrate ( 1 a ) is forced to pass through the substrate ( 1 a ) dislodging any trapped biogas.

1 - 7 . (canceled) 
     
     
         8 . A digester device, comprising:
 at least one digester ( 1 ), configured for treating a substrate ( 1   a ) with percolate ( 2   a ) and with a CO 2 -containing purge gas;   a percolate container ( 2 ), fluidly coupled to said at least one digester ( 1 ) via a percolate return line ( 21   b ) and a percolate supply line ( 21   a ), said percolate container ( 2 ) configured for providing said percolate ( 2   a ) to said at least one digester ( 1 ),   at least one biogas withdrawal line ( 12 ,  23 ), configured for removing biogas that has been generated in at least one of the digester ( 1 ) and the percolate container ( 2 ) during a substrate ( 1   a ) fermentation period, and for providing said removed biogas to a biogas treatment device ( 3 );   a biogas treatment device ( 3 ), configured for treating biogas, whereby the biogas treatment device ( 3 ) is configured for supplying CO 2 -containing exhaust gas generated during the treatment of biogas to said substrate ( 1   a ) in said digester ( 1 ) via an exhaust gas line ( 31 ) fluidly coupled to a purge line ( 4 ), said purge line ( 4 ) configured for introducing CO 2 -containing purge gas into the digester ( 1 ), for removing any biogas in said substrate ( 1   a ) that was generated in the digester ( 1 ) during e fermentation period, whereby the CO 2 -containing purge gas is introduced into the digester ( 1 ) such that said CO 2 -containing purge gas passes through the substrate ( 1   a ) in the digester ( 1 ), wherein CO 2 -containing purge gas is introduced Under pressure into a bottom region of the digester ( 1 ) and this into a bottom region of the substrate ( 1   a ) through one or more purge ports such that any biogas that is present in the substrate ( 1   a ) is dislodged into a substrate-free volume ( 1   b ) of the digester ( 1 ) above the substrate ( 1   a ) for subsequent collection and removal.   
     
     
         9 . (canceled) 
     
     
         10 . The digester of  claim 8 , wherein the CO 2 -containing purge gas is distributed into the bottom of the digester ( 1 ) such that the CO 2 -containing purge gas passes through the substrate ( 1   a ) essentially uniformly from bottom to top. 
     
     
         11 . The digester of  claim 8 , wherein said biogas is generated in both the digester ( 1 ) and in the percolate container ( 2 ). 
     
     
         12 . The digester of  claim 8 , wherein said digester is configured to first provide said CO 2 -containing purge gas into the bottom of the digester ( 1 ) via said purge line ( 4 ) and subsequently provide fresh air into the digester ( 1 ) via said purge line ( 4 ). 
     
     
         13 . the digester of  claim 8 , wherein said digester is configured after the conclusion of a purging process with CO 2 -containing gas, to cause a biogas withdrawal port ( 12   a ) to close while a venting line Port ( 11   a ) to open.